Monday, December 3, 2007

USABILITY TESTING

USABILITY TESTING

This testing is also called as ‘Testing for User-Friendliness’. This testing is done if User Interface of the application stands an important consideration and needs to be specific for the specific type of user. Usability testing is the process of working with end-users directly and indirectly to assess how the user perceives a software package and how they interact with it. This process will uncover areas of difficulty for users as well as areas of strength. The goal of usability testing should be to limit and remove difficulties for users and to leverage areas of strength for maximum usability. This testing should ideally involve direct user feedback, indirect feedback (observed behavior), and when possible computer supported feedback. Computer supported feedback is often (if not always) left out of this process. Computer supported feedback can be as simple as a timer on a dialog to monitor how long it takes users to use the dialog and counters to determine how often certain conditions occur (ie. error messages, help messages, etc). Often, this involves trivial modifications to existing software, but can result in tremendous return on investment. Ultimately, usability testing should result in changes to the delivered product in line with the discoveries made regarding usability. These changes should be directly related to real-world usability by average users. As much as possible, documentation should be written supporting changes so that in the future, similar situations can be handled with ease.

EXPLORATORY TESTING

EXPLORATORY TESTING

This testing is similar to the ad-hoc testing and is done in order to learn/explore the application.

Exploratory software testing is a powerful and fun approach to testing. In some situations, it can be orders of magnitude more productive than scripted testing. At least unconsciously, testers perform exploratory testing at one time or another. Yet it doesn't get much respect in our field. It can be considered as “Scientific Thinking” at real time

AD-HOC TESTING

AD-HOC TESTING

This type of testing is done without any formal Test Plan or Test Case creation. Ad-hoc testing helps in deciding the scope and duration of the various other testing and it also helps testers in learning the application prior starting with any other testing. It is the least formal method of testing. One of the best uses of ad hoc testing is for discovery. Reading the requirements or specifications (if they exist) rarely gives you a good sense of how a program actually behaves. Even the user documentation may not capture the “look and feel” of a program. Ad hoc testing can find holes in your test strategy, and can expose relationships between subsystems that would otherwise not be apparent. In this way, it serves as a tool for checking the completeness of your testing. Missing cases can be found and added to your testing arsenal. Finding new tests in this way can also be a sign that you should perform root cause analysis. Ask yourself or your test team, “What other tests of this class should we be running?” Defects found while doing ad hoc testing are often examples of entire classes of forgotten test cases. Another use for ad hoc testing is to determine the priorities for your other testing activities. In our example program, Panorama may allow the user to sort photographs that are being displayed. If ad hoc testing shows this to work well, the formal testing of this feature might be deferred until the problematic areas are completed. On the other hand, if ad hoc testing of this sorting photograph feature uncovers problems, then the formal testing might receive a higher priority.

LOAD TESTING

LOAD TESTING

The application is tested against heavy loads or inputs such as testing of web sites in order to find out at what point the web-site/application fails or at what point its performance degrades. Load testing operates at a predefined load level, usually the highest load that the system can accept while still functioning properly. Note that load testing does not aim to break the system by overwhelming it, but instead tries to keep the system constantly humming like a well-oiled machine.In the context of load testing, extreme importance should be given of having large datasets available for testing. Bugs simply do not surface unless you deal with very large entities such thousands of users in repositories such as LDAP/NIS/Active Directory; thousands of mail server mailboxes, multi-gigabyte tables in databases, deep file/directory hierarchies on file systems, etc. Testers obviously need automated tools to generate these large data sets, but fortunately any good scripting language worth its salt will do the job.

STRESS TESTING

STRESS TESTING

The application is tested against heavy load such as complex numerical values, large number of inputs, large number of queries etc. which checks for the stress/load the applications can withstand. Stress testing deals with the quality of the application in the environment. The idea is to create an environment more demanding of the application than the application would experience under normal work loads. This is the hardest and most complex category of testing to accomplish and it requires a joint effort from all teams. A test environment is established with many testing stations. At each station, a script is exercising the system. These scripts are usually based on the regression suite. More and more stations are added, all simultaneous hammering on the system, until the system breaks. The system is repaired and the stress test is repeated until a level of stress is reached that is higher than expected to be present at a customer site. Race conditions and memory leaks are often found under stress testing. A race condition is a conflict between at least two tests. Each test works correctly when done in isolation. When the two tests are run in parallel, one or both of the tests fail. This is usually due to an incorrectly managed lock. A memory leak happens when a test leaves allocated memory behind and does not correctly return the memory to the memory allocation scheme. The test seems to run correctly, but after being exercised several times, available memory is reduced until the system fails.

BLACK BOX TESTING

FUNCTIONAL TESTING

In this type of testing, the software is tested for the functional requirements. The tests are written in order to check if the application behaves as expected. Although functional testing is often done toward the end of the development cycle, it can—and should, —be started much earlier. Individual components and processes can be tested early on, even before it's possible to do functional testing on the entire system. Functional testing covers how well the system executes the functions it is supposed to execute—including user commands, data manipulation, searches and business processes, user screens, and integrations. Functional testing covers the obvious surface type of functions, as well as the back-end operations (such as security and how upgrades affect the system).

Software Testing

Software Testing is the process used to help identify the correctness, completeness, security, and quality of developed computer software. Testing is a process of technical investigation, performed on behalf of stakeholders, that is intended to reveal quality-related information about the product with respect to the context in which it is intended to operate. This includes, but is not limited to, the process of executing a program or application with the intent of finding errors. Quality is not an absolute; it is value to some person. With that in mind, testing can never completely establish the correctness of arbitrary computer software; testing furnishes a criticism or comparison that compares the state and behaviour of the product against a specification. An important point is that software testing should be distinguished from the separate discipline of Software Quality Assurance (SQA), which encompasses all business process areas, not just testing.
White box and black box testing are terms used to describe the point of view a test engineer takes when designing test cases. Black box being an external view of the test object and white box being an internal view. Software testing is partly intuitive, but largely systematic. Good testing involves much more than just running the program a few times to see whether it works. Thorough analysis of the program under test, backed by a broad knowledge of testing techniques and tools are prerequisites to systematic testing. Software Testing is the process of executing software in a controlled manner; in order to answer the question “Does this software behave as specified?” Software testing is used in association with Verification and Validation. Verification is the checking of or testing of items, including software, for conformance and consistency with an associated specification. Software testing is just one kind of verification, which also uses techniques as reviews, inspections, walk-through. Validation is the process of checking what has been specified is what the user actually wanted